Lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction (BPO) are common in the aging male. There are few well-designed, long-term, mufti-center randomized clinical trials comparing the subjective and objective outcomes of minimally invasive surgical therapies (MIST). AIM 1.To participate in the collaborative Prostate Evaluation and Treatment Centers (PETCs) that will develop: a) Standardized assessment instruments for the diagnosis and classification of symptomatic BPH in men above the age of 50; b) Clinical trial protocols that will compare the outcomes of treatments to improve symptomatic BPH. The primary focus of Aim 1 is to incorporate our BPH research team as PETC. The PI and the BPH research team assembled for this project have had broad experience in the design, implementation and analysis of BPH research. We have successfully participated in 10 BPH trials including 2 VA Cooperative trials, pharmaceutical sponsored trials, a local investigator initiated trial, and both phases of the Medical Therapy of Prostatic Symptoms trials (MTOPS). Our patient retention and adherence has consistently been in the top 25 percent. The medical center hospitals provide more than an adequate number of patients to meet recruitment goals. AIM 2. To establish and implement a prospective randomized controlled trial for treatment of BPH that will: a) establish the treatment outcome for medical therapy versus minimally invasive therapy as the primary mode of therapy; b) determine which of the following predict successful treatment outcomes: 1) Patient characteristics including AUA symptoms score, uroflow rate, and prostate size; 2) Urodynamic parameters; 3) determine the cost of achieving the treatment outcome. The goal of Aim 2 is a randomized clinical trial (RCT) to evaluate the efficacy and effectiveness of the minimally invasive therapy of transurethral microwave thermotherapy (TUMT). Our hypothesis is that TUMT in patients with minimal or moderate symptoms secondary to BPH will be both more efficicacious and effective than medical therapy and reduce overall health care dollars expenditures. The RCT will compare the best arm of the current MTOPS trial to TUMT. TUMT was chosen as the MIST, because it meets the criteria of being truly "minimally invasive." Unfortunately, there has been lack of uniform entry criteria, lack of consistent follow-up and scarce data on long-term outcomes (effectiveness) and costs. The RCT will compare a sham TUMT and medical therapy to TUMT treatment in a double blind manner. Medical therapy was chosen over TURP for the comparison because there is more "overlap" of TUMT with this therapy than with transurethral resection of the prostate (TURP) (Figure 1). Health care economics dictate that the short and long-term costs of BPH therapy need to be addressed. The PI has enlisted the support of consultants who will assist in this important evaluation. The results of this analysis will be critical in allocating health care resources.